46/36 Chainset for Road, would you?

dyrlac

I love gear ratio questions, could yammer all day. 48T is a good big chainring.

My first proper road bike (all of 18 months ago) came with a 46/36 and a nine speed 12-26. Almost immediately, I found 46/12 to be too slow on the flat at what was *for me then* a comfortable cadence: 90 rpm at 46/12 only got you to 44kph (27.5mph). And I found 90 rpm hard to sustain for any length of time. So I changed it to 48/36 in pretty short order, which was better; although as I found myself heading uphill more often, I found 36/26 to be a bit of a limiting factor from time to time and I had grown to hate Sora. Long story short, I am changing that bike to a compact 50/34, with a 11 speed 11-28 at the rear.

apreading

48/34 would be ideal for me, with either 11-28 or 12-28 on the back. Trouble is, I am not sure you can get 48/34 in a good chainset that you can get for a sensible price? I have just bought Ultegra 50/34 for under £100 for example - dont think I can get a 48 for that.

bendertherobot

I had a google this morning for a 46t chainring for my Apex chainset.

Seems to be north of £80.

I paid £50 for the chainset.

ugo.santalucia

bendertherobot wrote:

I had a google this morning for a 46t chainring for my Apex chainset.

Seems to be north of £80.

I paid £50 for the chainset.

I bought a CX 70 46T ring for 20 quid in Germany... Rose, I think... 110 BCD

stevie63

So I just wanted to give an update on this. I went for an Ultegra 46/36 Chainset paired with 11-28 on the back and I have been for a couple of quick rides and all I can say is wow. For me at my level of fitness (nothing special average 16mph over winter and 17 during summer) this is what seems to be the perfect combo of ratios.

The speed of the front changes is brilliant and more importantly the disruption to my cadence is much smaller. Once on the big ring I can stay there for longer. In reality it doesn't make a jot of difference to how fast I can go but anything that makes riding more enjoyable is worth it in my eyes.

ugo.santalucia

stevie63 wrote:

The speed of the front changes is brilliant and more importantly the disruption to my cadence is much smaller. Once on the big ring I can stay there for longer.

You hit the nail on the head there... that is exactly the reason to go for 46 x 36

markhewitt1978

I'd be quite happy to go with smaller than 50 for the big ring, perhaps 46 or 48, but I wouldn't want bigger than 34 for the little ring, I need my hill climbing gears!

That said a 10 speed cassette with 14-30 would be ideal. I already run 12-30 and even then the amount of time I find myself in the 12T cog is very rare.

ugo.santalucia

markhewitt1978 wrote:

I'd be quite happy to go with smaller than 50 for the big ring, perhaps 46 or 48, but I wouldn't want bigger than 34 for the little ring, I need my hill climbing gears!

That said a 10 speed cassette with 14-30 would be ideal. I already run 12-30 and even then the amount of time I find myself in the 12T cog is very rare.

34 was introduced at a time when 27-28 were the biggest sprockets available. Now you can buy 30 and 32, which means 34 front is no longer needed

markhewitt1978

Speak for yourself. I use 34/30 all the time.

banditvic

I've just taken off a Sram Rival 22 46/36 chainset off of my new Pickenflick if anyones interested, unused but chain must have come off bike in box and slightly scratched stickers GXP bb.

stevie63

markhewitt1978 wrote:

Speak for yourself. I use 34/30 all the time.

If you already have a 50/34 chainset with a 5 bolt 110bcd then why not just wack on a 46 tooth outer ring which will probably be the cheapest way to go.

Cannock Chase

markhewitt1978 wrote:

...That said a 10 speed cassette with 14-30 would be ideal...

Yes it would.

I have a Ultegra 9 speed 14-25 on another bike so don't see any reason not to have a 14t as the smallest cog on a 10 speed.

Giraffoto

Absolutely I would - after a few calculations and a look through the catalogues of what was available, I settled on 46/36 at the front and 12-28 at the rear. My new bike has an 11-32 cassette that I stuck with (it's like a 12-28 with an extra cog each side) but I got the shop to change the rings for 48/36. It's perfect for me

ai_1

I have to say, front changes with Ultegra 6800 are pretty trivial so it doesn't bother me much if I need to move between chainrings relatively frequently. For flat rides I agree 36/46 makes a lot of sense. Before my current 50/34 & 11-18, 11 speed double setup I was using a 50/39/30 & 12-27, 9 speed triple. On flat stretches the triple did mean you could ignore the 30 and just change back and forth between 39 and 50 as needed. I currently live just west of Dublin which is rather flat, and I do lots of very flat rides. However, a short distance south are the Dublin/Wicklow mountains with a good selection of relatively challenging climbs. I like descending, and rarely if ever free-wheel even if I'm not putting a lot of power in. The 50-11 combo gets used pretty frequently but to be fair the 50-12 on the older bike never really held me back. So a 46/11 would do fine. On the steep climbs, some with stretches around 15-18%, I do need the 34/28. I've never had to get off and walk but I there are occasions when I'd welcome something a little smaller to fall back. So moving to 36 would mean I'd want a 30 on the back.
With an 11 speed cassette, an 11-30 range would be acceptable. The gaps are not unreasonably big. Still, I do like the gaps a bit smaller when feasible. I think the 50/34 compact with a 11-28 cassette is a good all-round solution for me. It gives a good range of gears on the hills while allowing me slightly smaller gaps on the cassette for flatter rides. When I'm riding reasonably hard on the flat I typically stay in the 50 and if I want the 34 it's no big deal. For more leisurely rides the 50/34 combo may not be ideal but it's not a horrible compromise either.

I think 46/36 and 11-30 on an 11 speed bike seems a very sensible setup. I'm not sure if I would find it better or worse than what I have now. I think for leisurely rides it would be better. For hard flat rides it might be just marginally worse. Mixed rides or on the hills it's hard to call. I may occasionally wish I had the 50-11 combo and the gaps are a little bigger for a similar total gear range. Unlike flatter rides it's rare enough you'll be cruising in or around the changeover point between small and big chainring so there's little to be gained.

Short version: I think 10+ speed cassettes and front shifting that is nice and smooth even with 16T chainring differences make this a much smaller issue than it would be otherwise. I've been very happy with both my 9 speed triple and my 11 speed 50/34 compact. I don't think I would have been so happy with a 9 speed 50/34 or even a 10 speed 50/34 if the front changes weren't good.

stevie63

The thing is even if the front changes are smooth and on my Apex setup they weren't great TBH, you still have to deal with the 47% difference when changing. That means if your cadence is 100 when changing it drops to 53 or you have to mess around changing several cogs at the back to keep things roughly the same.

With 46/36 that drops to 28% so now your cadence only drops to 72 or with one small shift at the back you don't even notice the interuption. As I mentioned earlier none of this is a deal breaker and it isn't going to make me faster but for the flat to rolling countryside that we have in East Anglia these are all the ratios that I am ever going to need. In addition if I was going to go somewhere a bit more hilly I can just change the inner ring for a 34 to give an extra low gear at the back.

keezx

So we see that some people still are riding triples, while some shifting is done at home.

Manc33

I have a 38t middle and 11-32t cassette, I pretty much never need to use the other rings unless I am going downhill or up a ridiculously steep hill. Then again as was eluded to above, bikes are mass produced with the same gear ratio's as the pro's. If their wattage output is around 350W-450W then mine must be a third of that.

I never thought a 52-38-24 chainset would work until I set it up but its fine. I think they just don't sell bikes with such large ranges because there's so much chain, small>small isn't really a workable gear and people will just change into that gear. When you start customizing your own bike that's when it comes to life.

As far as I can see road bikes are becoming more like MTB's all the time. :roll: Disc brakes, flat bar components, Shimano 105 cassettes going up to 32t... unheard of ten years back. I think a flat bar road bike makes the perfect commuter bike once you put some tyres on with a tread in something like like 25c/28c. Faster than a commuter bike thats for sure.